Forensics and Physics

202 Pages·2022·9.119 MB·English

by  Renata Holubova, Jiří Straus, Jana Slezáková

Forensics and Physics

Forensics and Physics
By
Renata Holubova, Jiří Straus
and Jana Slezáková
Forensics and Physics
By Renata Holubova, Jiří Straus and Jana Slezáková
This book first published 2022
Cambridge Scholars Publishing
Lady Stephenson Library, Newcastle upon Tyne, NE6 2PA, UK
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library
Copyright © 2022 by Renata Holubova, Jiří Straus and Jana Slezáková
All rights for this book reserved. No part of this book may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any means,
electronic, mechanical, photocopying, recording or otherwise, without
the prior permission of the copyright owner.
ISBN (10): 1-5275-8407-0
ISBN (13): 978-1-5275-8407-5
TABLE OF CONTENTS

List of Illustrations ................................................................................... vii

List of Tables .............................................................................................. x

Introduction ............................................................................................... xi

Chapter One ................................................................................................ 1
Forensic Trasology
Introduction ........................................................................................... 1
1.1 Searching for and securing of trasological tracks ........................... 6
1.2 Biomechanical content of trasological traces ................................ 15
1.3 Physics behind trasology ............................................................... 27
1.4 Walking and Physics ..................................................................... 40

Chapter Two ............................................................................................. 48
Biomechanics of Falls
Introduction ......................................................................................... 48
2.1 Biomechanical classifications of falls ........................................... 49
2.2 Injuries caused by falls .................................................................. 53
2.3 Analysis and experimental results ................................................. 66
2.4 Standing on a pad .......................................................................... 78
2.5 Human reaction time ..................................................................... 85

Chapter Three ......................................................................................... 107
Dactyloscopy
Introduction ....................................................................................... 107
3.1 Searching, visibility and securing dactyloscopic traces .............. 110
3.2 Examining of dactyloscopic traces .............................................. 113
3.3 Physics behind dactyloscopy ...................................................... 121
3.3.1 Optics ................................................................................. 121
3.3.2 Molecular physics-adhesion and cohesion ......................... 126
vi Table of Contents
Chapter Four ........................................................................................... 138
Forensic Ballistics
4.1 Forensic ballistics as a scientific discipline ................................. 138
4.2 Physics behind the ballistics ....................................................... 146
Appendix: Mathematics .......................................................................... 159
Differential and vector calculus ........................................................ 159
References .............................................................................................. 183
About the Authors .................................................................................. 188
LIST OF ILLUSTRATIONS

Figure 1-1. Types of soles
Figure 1-2. Heels and sole
Figure 1-3. Traces of vehicles
Figure 1-4. 3D trasological trace
Figure 1-5. Stride length and two-step locomotion
Figure 1-6. Plantogram with significant parameters
Figure 1-7. Dependence of body height on significant parameters of the
plantogram
Figure 1-8. Several types of plantograms
Figure 1-9. Bar foot trace
Figure 1-10. Kepler´s law of areas
Figure 1-11. Gravitation
Figure 1-12. Throw vertically upwards
Figure 1-13. Horizontal throw
Figure 1-14. Oblique up throw
Figure 1-15. Movement of the centre of gravity
Figure 1-16. Diagram of the human body
Figure 2-1. Classification of falls
Figure 2-2. The impact of the body and the representation of the primary
(triangle) and secondary injury (wheel)
Figure 2-3. Evaluating the course of the fall from the height
Figure 2-4. Fall schedule
Figure 2-5. Biomechanics of falls
Figure 2-6. Falling patterns of standing jump and running jump above the
jumping level: Running and standing jump are intimated at initial
velocities of 9.15 and 2.70 m·s-1 at initial angles of 21 at 38 deg above
the jumping level
Figure 2-7. Falling patterns intimated at various angles of jump at initial
velocities of 2.70 m·s-1 (A) and 9.15 m·s-1 (B): Maximal horizontal
movement can be achieved at about 40 deg; the angle at 50 deg or over
starts to minimize the horizontal movement
Figure 2-8. Falling patterns intimated at various angles of jump at initial
velocities of 2.70 m·s-1 (A) and 9.15 m·s-1 (B), falling from height of
100 m
viii List of Illustrations

Figure 2-9. Falling patterns intimated at various angles of jump at initial
velocities of 2.0 m·s-1 (A) and 9.5 m·s-1 (B), falling from height of 100
m
Figure 2-10. Range of maximal horizontal movement of standing jump
and running jump at angles between 0 and 40 deg
Figure 2-11. Body mass center trajectory comparison as relation of
different kind of falls
Figure 2-12. Unprotected fall
Figure 2-13. Scheme of dropping the body from stand to pad
Figure 2-14. Typical course of head velocity and center of gravity over
time
Figure 2-15. Typical course of the angular velocity of the head and the
angular velocity of the resting limb over time, in case of restored
stability
Figure 2-16. The course of the spontaneous fall of figurant
Figure 2-17. Categorization of reaction times
Figure 2-18. The process of motor response formation for each type of
reaction time, according to Donders
Figure 2-19. Structure of the total duration of the action
Figure 2-20. Dependence of reaction time on the intensity of the auditory
stimulus
Figure 2-21. Reaction time dependencies on alcohol level - maximum
alcohol level 0.6 ‰
Figure 2-22. Reaction time dependencies on alcohol level - maximum
alcohol level of 1.2 ‰
Figure 3-1. Comparison of the secured track and the captured fingerprint
Figure 3-2. Ridge characteristics
Figure 3-3. Visibility of the dactyloscopic trace with finely groung ferric
oxide
Figure 3-4. Visibility of the dactyloscopic trace by reaction with
ninhydride and by iodine vapour
Figure 3-5. Papilary lines
Figure 3-6. A compound microscope
Figure 3-7. Running rays
Figure 3-8. Comparative microscope for forensics
Figure 3-9. Ken – a – vision comparative microscope
Figure 3-10. Comparison microscope - image
Figure 3-11. Measurement of adhesion forces
Figure 3-12. Surface tension - forces
Figure 3-13. Liquid wetting the solid body
Figure 3-14. A liquid that does not wet the solid body
Forensics and Physics ix
Figure 3-15. A drop of liquid
Figure 3-16. Surface tension of a liquid drop on another liquid
Figure 3-17. Capillary elevation and depression
Figure 3-18. Adhesion of dactyloscopic powder to a dactyloscopic brush
Figure 3-19. Adhesion of dactyloscopic powder to the solid surface
Figure 3-20. Adhesion of dactyloscopic powder to a surface with a
dactyloscopic trace
Figure 4-1. Coriolis force
Figure 4-2. Air flow around the ball
Figure A-1. Magnitude of the instantaneous velocity of the point [x; y],
which moves along the curve k at time t
Figure A-2. Geometric meaning of the derivative
Figure A-3. Tangent and normal of the graph of the function
Figure A-4. Geometric interpretation of Rolle's theorem
Figure A-5. Geometric interpretation of the Lagrange’s theorem
Figure A-6. Local and global extremes of function
Figure A-7. Oriented line
Figure A-8. Bound geometric vectors
Figure A-9. Non-collinear vectors
Figure A-10. Collinear vectors (same oriented)
Figure A-11. Collinear vectors (not same oriented)
Figure A-12. Multiple of the bound geometric vector a) concordant
direction b) non concordant direction
Figure A-13. Free geometric vectors
Figure A-14. The sum of free vectors
FigureA-15. Orthonormal bases of vector spaces
Figure A-16. The scalar product of the vectors u, v